I broke my tank down 2 years ago but due to moving away to school and a bunch of other reasons i still had rock in my sump that dried out and i still had some rubble in my sandbed that i left dried up for the last 2 years, i plan on using the rock in my new biocube but im not sure if i can just throw it in even though it has been dried for 2 years or if there was still stuff on it that i needed to kill before adding to my new tank